Gear upgrades?!

First time ever going bowzon. Looking for some upgrades to make it better!
I eventually want to swap out to a faith + TMight A1 Vigor merc for more FRW.. but curious what pieces I should start upgrading! (I know some more dmg/ar charms too)

Sitting on about 3.5hr
Oh, also — what should the skill tree look like? What skill do I use for map bosses? I feel multi is under-performing against them